Lithium ion secondary batteries are rechargeable batteries often used to power mobile communication devices and portable electronic devices. Without wishing to be bound by the theory and generally speaking, a lithium ion secondary battery may be charged by providing an external electrical power source that forces, or otherwise moves, lithium ions from a positive electrode to a negative electrode. During discharge, the lithium ions may carry current back from the negative electrode to the positive electrode.
Prior materials used as a negative active material within the negative electrode may include lithium metal, carbon materials such as coal and graphite, and tin (“Sn”) materials, as well as complex oxidations of Sn or Sn-based alloys and graphite. Without wishing to be bound by the theory, Applicants believe that Sn negative materials exhibited a relatively higher specific capacity than, for example, some carbon materials, including graphite materials. For example without wishing to be bound by the theory, the theoretic capacity of metal Sn may be about 994 milliampers per gram (“mAh/g”); the theoretic capacity of SnO may be about 600 mAh/g; and the theoretic capacity of SnO2 may be about 777 mAh/g. Further, without wishing to be bound by the theory, Sn may produce about 3 times volume change during the charging and discharging process, which may cause electrode peeling off, powderizing and further cause a drop in capacity and cycling performance.